Aik-heating furnace



y tial, to eifect the object.

UNITED. STATES PATENT y,

G. CHILSON, OF BOSTON, MASSACHUSETTS.

AIR-HEATING- FURNACE.

Specification of Letters Patent No. 7,780, dated November 19, 1850.

To all lwhom t may concern Be it known that I, GARDNER CHiLsoN, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in farming and Ventilating Furnaces for Buildings, and that the following is a full, clear, and exact description of the principle or character which distinguishes them from all other things before known, and of the usual man` ner of making, modifying, and using the same, reference being had to the accompanying drawings, which form a part of the same.

Figure l is a vertical section; Fig. 2, an elevation of the furnace with a portion of the front removed. Eig. 3 the annular chamber modified without the cross pipe- Fig. 4 is a horizontal section through the line (fw To make a perfect furnace for warming, and ventlating, buildings especially when anthracite or other coal or wood, is the fuel to be used, I find from my long experience that certain requisites, are absolutely essen- These I will first enumerate, the more clearly to illustrate my invention, and itsl purposes; for the construction, although reduced to great simplicity is t-he work of much time, experience, and labor requiring for its perfection a large expenditure of money. The most prominent things to be observed, are first a broad, shallow, fire surmounted by a large chamber above, of proper proportions, so that the direct rays of heat from all parts of the fire, may impinge upon, and heat the surface in every part alike; and draw olf the products of combustion equally, from all sides, into a chamber or other receiver, in which it should be made to circulate more sluggishly, before leaving the furnace. The pressure produced by checking the currents from the secondy chamber, I find, especially important in abstracting all the heat, from the fuel to a useful purpose.

The above desiderati, must be combined with an apparatus, that will secure a constant supply of fresh air, so arranged as to conduct off intothe appartments to be warmed and ventilated the greatest amount of heat, from the fuel consumed, and producing a fresh, healthful, salubrious atmosphere perfectly free from the deleterious effects, produced by red hot iron. All the above eifects, must be accomplished within a reasonable space, in height, and other dimensions otherwise the furnace, could not be introduced into all buildings, and a due regard must also be paid, in the construction to its durability, the tightness of the joints, and economy in burning fuel. As there is such a variety of important elements, Iin the accomplishment of the object in view, the difficulty of overcoming them all, in making a simple structure will be perceived to be very great. The mode that vI have discovered to be the best adapted to the purpose, will be detailed in the following description; and is the result of some years approximate labor.

The iire pot (a) may be of circular form, and about one half of the height of the common ones, say about seven inches, more or less in depth; its figure is an inverted, truncated cone, and displays asurface of re, two or three times broader than ordinary fire pots. This portion of the furnace, I line with soap-stone, or iire bricks to prevent the fuel from coming in contact, with the iron, thus preventing the iron from becoming red hot. The inclination of the sides of the pot, keeps the coal compact as it burns down, and thus secures itsI entire consumption. Heretofore it has been objected that bylining the ire pot, with soap stone or brick, there was a waste of heat, as it was anon-conductor; and that was found to be the fact, in deep, straight, cylinders; but 'by forming them according to my plan, shallow and iaringno inconvenience arises from that source, which is an important reason for its adoption. Another pointis the fact that this broad, shallow fire, admits air freely to all parts of the coal, and prevents it from clinkering, which always takes place in a deep pot, if lined with soap stone, or bricks.

The fire grate (b) used in this furnace, and situated at the bottom of the 'fire pot, is the lever grate, heretofore patented by me; itis attached to, and turns in, boxes attached to the under side of the bed `plat-e, (c) on which the fire pot rests. Over the fire pot, I place a large corrugated cylinder,

(CL) of wrought, or cast iron resting onv groove formed on the upper side of a flange',

at that point into which the lower edge of a ring, (6,) fits.; around which at properv intervals, are six inverted' conic sections, (f) projecting. The top edge of this ring (e) is formed into a similar groove, or channel, as that just above described. An arched dome or top plate, (g) fits on to this ring having cylindrical pipes, (it) six in number projecting up from its edges; one half the diameter of said pipes, being made to project over the edge of thev plate, to correspond with the conic sections above named. These are the exit pipes from the tire chamber, and draw the products of combustion equally from the center, to all sides of the chainber, instead of concentrating them upon one point, and thus over heating it. The tops of these pipes (71.) are formed, into grooved cups in the same manner, as the parts below, for the purpose of forming sand lute joints, to allow the different plates, to freely expand, and contracty without strain or inury.

J The whole'of the above described structure is surmounted, by a cylindrical annular chamber, (which is cast in one piece, or may be cast in sections,) with six openings on its under side, surmounted by collars that fit into the grooves, on the ends of pipes (n). Across the diameter of this ring, (z') there is a single pipe (la) which is of the same bore as the ascending pipes, (it). This pipecurves upward at the center, high enough to admit the attachment, of a descending exit pipe (3,) at the center, on the under side, and above ,they dome of the fire chamber; by this construction it will be perceived, that there are six openings for the products of combustion, into" the largey annular chamber, which has the same larea 1n its cross section, as the six ascending pipes; and only two pipesv of the same ca.

pacity, as `Aa` pipei (L) out of it, which two are united at the center, by only one pipe of the same diameter, as one of the ascending pipes; (h) through which the smoke etc. is drawn off tothe chimney. I thus effect many important objects, first I draw the heated gases from all parts of thel fire chamber, equally as before stated, and collect them in a capacious chamber, above where they attaina considerable degree of pressure, that fully insures the equal heating of all parts, of the annulus, fromv which they are allowed only gradually to escape,

after being fully exhausted of their` heat,. into a descending pipe; which is so cont-f' bined with, and proportioned to this annu#` lar chamber, as to make all the pipes draw alike. These parts are so arranged,` as to have a current of air over their whole surface, without any placeforvit to stagnatie. l

The course of the airwill be explained, after the Vdescription of the mode of setting, the furnace.

The walls of the air chamber are double, with an air space between them;.the cold exterior air isconducted in, through both walls to an air trench, (m,`) below the bed plate (0,), and around the ash pit (11.); thence a portion of the air, 'passes up into the air chamber, (0,) impinging against, and passing up over the surface of the cylinder, above the firepot; thence it rises against the annular chamber, where it'divides, one portion going inward, over the dome and around the central pipes, while the other continues up around the outside ofthe chamber, and is drawn off through short pipes, (p) into the hot air pipes, (p) to the several Vapartments to be heated.

I have just described the courseof the air, from thatv portion of the trench, that passes through the hot air chamber, but there'is another portion, passing from the cold air trench that enters between the walls, through openings (g) made laterally, through the inner wall (1') whence it ascends between the walls carrying up with it, all the heat that radiates through the inner wall, and passes out around the pipe, (72) into a common conductor (p) where it commingles, with the air from the furnace. It is,v obvious that the air, between the walls will only rise when heated,-and its rapidity of motion is just equal to the amount of heat radiated through the inner wall. This entirely prevents the radiation of Lheat into they cellar when the furnace is located` there and where the heat would not'only be lost,` but would absolutely be detrimental, by4 causing vegetables `to decay, and spoil anything that is required to be kept cool. In double walls as at the top, and then descends between-the walls, passing through the inner wall, .to the furnace and thence up to the apartments to be heated. In taking this course it will be perceived that the'heat passing throu h heretofore constructed, the air is admitted` the inner wall mustl be carried down by t e current or lost. Of course a hi hly heated column of air cannot be readily drawn down, and consequently the supply of air is retarded. This increases the diiculty, and

causes the inner wall to become hotter, till 1 described, it can be cast with the cylinder:

The annular chamber may also be modified, although I deem the exact form I described as the best. For instance, it may be made without the cross pipe, and have a greater or less number of inlets, without wholly losing its beneficial eects. The advantages of curving the central cross pipe, (16,) upward are manifold; rst it gives room to attach the exit pipe, below without adding to the elevation of the furnace. The ring formed chamber could not be cast whole, without this curvature, which is a matter of great importance, (although it may be cast in sections) and by its upward inclination, from its'junction with the annular chamber, the draft is more perfect than it would be if it passed off horizontally. The surfaces are all curved in this furnace, which enables them to withstand expansion; and contraction; this is further aided by the position of the descending smoke pipe, in a very warm place.

Having thus fully described my air warming and Ventilating furnace, what I claim therein as new, and desire to secure by Letters Patent, is

l. The annular chamber constructed, and arranged substantially in the manner, and for the purposes set forth-with or without the cross pipe.

2. I also claim the mode of conducting off the products, of combustion from the fire through ascending pipes, (la) into an annular chamber, and thence into a central descending pipe, to their exit; and the surfaces being all so constructed of a curved figure, as to allow a diverting influence, and free circulation to the exterior air in the air chamber, to be warmed without over-heating it; while itis by the arrangement of parts, forced to implnge directly against the heated surfaces.

3. I also claim the method of setting the furnace, consisting of a double walled chamber, the inner wall of which, encloses a cold air trench, supplied from without, that surrounds the ash pit, with openings at its top for the proper admission of air, into the air chamber around the furnace, and with lateral openings, into the space between the walls to cause an upward current, which is connected, with the warm air pipes leading to the apartments, by means of which a constant, and pure supply of air is insured, and the heat greatly economized.

GARDNER CHILSON.

Witnesses:

J. J. GREENOUGH, RoWLAND ENIs. 

